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major reference

Isotopes are atoms that have the same atomic number (and, hence, generally the same chemistry) but different mass. The difference in mass becomes chemically important in certain instances. For example, when a carbon-hydrogen bond is replaced by a carbon-deuterium bond (deuterium being…

atomic spectra

These effects are known as isotope shifts and form the basis for laser isotope separation. For light atoms, the isotope shift is primarily due to differences in the finite mass of the nucleus. For heavier atoms, the main contribution comes from the fact that the volume of the nucleus increases…

hydrogen isotopes and reaction rate

…that the chemical differences between isotopes are negligible. For hydrogen, however, chemical reactions involving the different isotopes proceed at measurably different rates. These kinetic-isotope effects can be utilized in detailed studies of reaction mechanisms. The rates of reactions of compounds containing deuterium or tritium are usually less than those of…

hyperfine structure

…is called isotope structure, or isotope shift. These spectral lines are sometimes referred to as hyperfine structure but may be observed in an element with spin-zero isotopes (even atomic and mass numbers). Isotope structure is seldom observed without true HFS accompanying it.